What is the rationale for setting ranges for color and fill in charts?

For column, bar, pie, and column and line chart types, there are options to set the data ranges for border color and for fill color.

What is the point of specifying ranges for border color and fill color in charts? After all, columns, for example, would have a default color that reflects the Y value. Why choose a fill color range that is different from the Y value?

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